Electrostatic speaker

Abstract

An electrostatic speaker capable of relaxing a restriction on the allowable amplitude of a diaphragm while maintaining the linearity of a force acting on the diaphragm. The electrostatic speaker mainly includes electrodes opposed to each other, a diaphragm, and elastic members interposed between the diaphragm and the electrodes. The elastic members have an elastic characteristic that generates a restorative force corresponding to higher order terms of an electrostatic force generated by the electrodes and acting on the diaphragm.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention relates to the construction of an electrostatic speaker.[0003]2. Description of the Related Art[0004]There is known a speaker that is called an electrostatic speaker (capacitor speaker). Since the electrostatic speaker is relatively simple in construction, attention has been paid to the points that the electrostatic speaker can be designed to be light in weight and compact in size and easily handled theoretically and so forth. Typically, the electrostatic speaker is comprised of two parallel flat electrodes facing each other with a gap therebetween and an electrically conductive sheet member (hereinafter referred to as the diaphragm or the vibrating membrane) inserted between the electrodes and having both ends thereof fixed to a chassis of the speaker (i.e., the typical electrostatic speaker is of a push-pull type). When a predetermined bias voltage is applied to the diaphragm to change the voltag...

AI Technical Summary

Benefits of technology

[0016]The present invention provides an electrostatic speaker capable of relaxing a restriction on diaphragm's allowable amplitude while maintaining the linearity of a force acting on the diaphragm of the speaker.

[0018]According to the present invention, a restorative force that cancels a third order strain is exerted from the interposed elastic members onto the diaphragm, and as a result, the linearity of the force acting on the diaphragm is kept maintained, even if the amplitude (allowable displacement range) of the diaphragm increases.

Problems solved by technology

Due to characteristics of these two forces, an allowable amplitude of the diaphragm is limited as will be described below, which causes a problem.

When the diaphragm 103 is in that region, there occurs the aforesaid problem of the diaphragm contacting with the electrode or being broken.

Even if the risk of the diaphragm contacting with the electrode or being broken is eliminated, there remains an acoustic characteristic problem.

However, in that case, there occur problems that the electrostatic force acting on the diaphragm decreases to thereby lower the output sound pressure and the voltage to be applied across the electrodes must be large enough to secure a predetermined output sound pressure.

Thus, it is difficult for the prior art electrostatic speaker to have both the expanded amplitude (the expanded allowable displacement range) of the diaphragm and the linearity of the force acting on the diaphragm, which prevents the electrostatic speaker from being improved in performance.

Images